The device disclosed by this invention relates generally to the field of safety equipment for use in securing persons while traversing vertically inclined surfaces at elevated heights.
More particularly, this invention discloses an apparatus to be used by climbers in ascending and descending trees or, for that matter, any vertically inclined surface which is generally circular in character.
In situations where an individual is engaged in activity at on an elevated surface, it is common to wear some form of fall restraint belt or harness to tether the individual to the elevated surface. The purpose is quite simple. Should the individual fall or slip, the user will only move a short distance and become suspended upon the vertical member thereby avoiding a fall to the ground and the potentially catastrophic injuries which may result from such an event. Examples of where a safety harness system would be warranted include a hunter in an elevated tree stand or a power line worker tethered to a telephone pole.
There have been various safety devices defined for use by lineman and telephone pole climbers. For example, Pat. No. 869382 (Newton), 1120496 (Holsclaw), 1721517 (Jacobs), 2920714 (Johnson), 3407898 (Johnson), and 3840091 (Conlon). Generally, these inventions define a passive belt type system which relies upon the use of teeth or other biting elements to engage the pole at the time of a fall. In response to these limitations other embodiments have been defined. Sulowski (5,141,074) discloses a strap assembly reliant upon an elastic tensile member under tension to engage a pole with the tension member being disengaged during the climbing process.
Harnesses and safety straps as existing generally provide a degree of increased safety but only when used properly. Most users commonly affix themselves to an anchor once achieving a desired height. However, it would be beneficial to have a system which not only protects the user at a selected height but also during the climb and descent. At any stage of the climb or descent, human error such as a slip or equipment malfunction may result in significant injury.
Safety harnesses are manufactured in many forms and configurations and include straps made from rope, webbing, or cloth. Nearly any material may be used as long as there is sufficient material strength to provide the requisite strength in a fall situation. Also, it is important to select a material capable of withstanding the elements and, perhaps most importantly, the continuous abrasion and friction sustained by the material due to the constant relocation, placement, and manipulation on rough vertical structures such as for example a wooden telephone poles or heavily barked trees. On the other hand, materials must also be suitable for smoother surfaces shown on a concrete telephone pole or smooth barked tree such as a young cherry tree.
Natural elements such as ice, snow, rain and even darkness increase the risk of danger for climbers. Also, human emotion such as excitement or fear may play a part in a serious injury while climbing. The use of a movable anchoring system would help to alleviate those types of injuries.
Current safety systems are not readily adaptable for use during the actual climbing or descending of the climber. The current art is more defined as protecting an individual once a desired height is achieved. Modern ropes and restraints are problematic when traversing up and down because of irregularities and hindrances in the surface, gravity, roughness of the surface and size of the vertical member. Current art mechanisms also have some very significant limitations when used on a particularly smooth surface.
Hence, it would be most beneficial to have a safety restraint system easily usable while climbing or at rest in fixed position.
One very significant use of restraint systems is by hunters or nature enthusiasts in the placement of portable tree stands in trees during hunting or nature viewing endeavors. In fact, portable tree stands are in wide spread use and becoming increasingly popular. They are carried through the woods and used at any previously undetermined location. One simply walks through the woods and climbs to a suitable height without any previous thought as to safety measures or, for that matter, the suitability of the tree for climbing. Unfortunately, placement of a portable stand is an arduous task. Most tree stands are manufactured so the hunter is able to use the geometric configuration of the stand to enable climbing and placement. A standard tree stand generally has an upper and lower climbing member. Each member has a cable or other means to attach to the tree encircling the tree and both members have multiple toothed or biting member “prongs” or feet like structures which are placed against the tree. The climbing members are set in a cantilevered position. The hunter flexes and moves the upper member (while ascending) in relation to the tree using a scissor like jerking motion. Placement of the prongs or feet against the tree allows the member to be “jerked” to a higher or lower location. Once in place the lower member (while ascending) is then raised. The process is repeated until a desired height is achieved. The movement is not very great for any one “jerking” motion and the act is quite physical. To protect the hunter against a fall during this climbing phase, manufacturers normally equip the tree stand with a restraint strap capable of attachment to the hunter and the tree. Attachment from the tree is normally through a carabineer, d-ring, buckle, etc. onto a vest or belt worn by the climber. Some only use a simple rope system and the rope system is nothing more than a rope with a slip knot which encircles the tree. The rope is loosened by the hunter every time any movement up or down is desired. The hunter then relocates the rope to the new desired location by hand. This simple system may provide some protection but is a time consuming and difficult task which, in itself, poses safety concerns. For example, in situations where heavy bark or other obstructions are encountered, relocation of the slip knot and rope is a very requiring the use of both hands.
Some of the above limitations have been recognized and there have been attempts to define a more appropriate product. For example Yerger (6,206,138) has described an improved system less likely to interfere with the climbing motion and, therefore, more likely to be used in the tree climbing process. However, Yerger still does not overcome the significant obstacles of the prior art relating to safety devices for hunters utilizing tree stands. This is evident from the fact current models of tree stands are normally provided only with the simple slip knot system described in this Background and Summary of the Invention.